So called “sippy cups”, such as used by infants and toddlers and other persons having difficulty drinking from a conventional cup or glass, commonly make use of a valve located within the lid of the sippy cup. The valve is located at or adjacent the spout and serves to prevent liquid egress therethrough except when the user of the sippy cup sucks on the spout to withdraw the liquid. Thus, such valves serve to keep the liquid contents isolated from the ambient surroundings, while also preventing spillage or leakage through the spout. Some sippy cups make use of valves which are permanently secured to the lid and thus form a non-removable portion of the sippy cup. While that arrangement reduces the risk of loss of the valve, it suffers the drawback of rendering the sippy cup difficult to effectively sanitize completely, e.g., mold and bacteria may build up in portions of the sippy cup assembly which are difficult if not impossible for cleansing liquids to reach when the sippy cup is washed in a dishwasher. To overcome that drawback various sippy cups make use of a removable unitary valve that is constructed of a resilient and flexible material, e.g., silicone rubber or a thermoplastic elastomer. That valve is typically releasably mounted within a hollow interior portion of the sippy cup lid. The thickness of the valve effectively creates a dam around its periphery in which a portion of the liquid contained within the sippy cup will be trapped if the sippy cup is completely inverted vertically when the user drinks from it. This dam effect thus prevents all of the liquid held within the sippy cup from being drunk. Obviously, this is less than desirable. Another drawback with prior art removable valves for sippy cups results from the fact that the valve may become lost or misplaced. In this regard, sippy cups making use of removable valves are typically cleaned by disassembling all of the components, e.g., the lid or cap is removed from the cup and then the valve is removed from the lid or cap, whereupon the disassembled components can then be placed in a dishwasher to wash and sanitize them all. Given that many repeated washings, and hence many repeated disassembles of the sippy cup components, are likely to be accomplished over the life of the sippy cup at some point the valve assembly may become lost or misplaced.
Accordingly a need exists for a removable sippy cup valve which overcomes the disadvantages of prior art removable sippy cup valves. The valve of this invention addresses that need.